0 Assigned ID: 423 ----- Attempting Submission 1 (Fri Apr 05 13:11:14 GMT 2019) ----- HST Phase I Proposal 423 (GJ9827b_HST.apt) successfully submitted. Receipt: # 423-1 Your proposal could not be saved. Submission aborted. ----- Attempting Submission 2 (Fri Apr 05 18:36:23 GMT 2019) ----- HST Phase I Proposal 423 (GJ9827b_HST.apt) successfully submitted. Receipt: # 423-2 Phase range has been extended to an earlier start phase in both visits -315430690 ----- Attempting Submission 1 (Tue Jul 16 16:11:25 GMT 2019) ----- HST Phase II Proposal 15859 (GJ9827b_HST.apt) successfully submitted. Receipt: # 15859-1 ----- Attempting Submission 2 (Wed Oct 30 12:20:50 GMT 2019) ----- HST Phase II Proposal 15859 (GJ9827b_HST.apt) successfully submitted. Receipt: # 15859-2 ----- Attempting Submission 3 (Fri Nov 29 10:40:38 GMT 2019) ----- Traveling across the valley: comparative exoplanetology in the GJ 9827 system The transition between rocky and volatile-rich planets is one of the most topical questions. The valley found to split the population of small close-in planets into 2 size regimes is thought to originate from atmospheric escape: some planets lose their atmosphere while others retain their volatile species. The 3-planets system orbiting GJ9827 spans the breadth of the valley: GJ9827c is on its low-radius side, and likely lost its volatile envelope; GJ9827b may be one of the few planets to have formed without an envelope within the valley, or it could have a water-rich envelope resilient to escape; GJ9827d is on the large-radius side, and the most favorable for atmospheric escape detection. GJ9827 is one of the few multi-planet systems whose star is bright and close enough for Ly-alpha transit spectroscopy. GJ9827b is being observed as part of an ongoing HST/UV program, and we propose to complete the exploration of the system by observing 2 transits of GJ9827d with STIS in the Ly-alpha line (10 HST orbits in total). The planet is sufficiently irradiated to evaporate, but a much larger hydrogen escape is expected from a H/He atmosphere compared to a water-rich envelope, both proposed to explain GJ9827d properties. Detecting a giant hydrogen cloud would thus favor an H/He atmosphere, while a non-detection or low hydrogen escape would favor a water-rich envelope acquired beyond the snowline. The program will constrain the nature of GJ9827d and the origin of the GJ9827 system, improve our understanding of the role played by evaporation in the transition from mini-Neptunes to super-Earths, and inform the community for an in-depth characterization of the GJ9827 planets with JWST This program consists in 2 visits of 5 HST orbits each. In each visit, we will observe the transit of an exoplanet (GJ9827d) in front of its host star. Transits occur every 6.2 days (the orbital period of the planet) and last for 1.2 hours. The goal is to search for a hydrogen exosphere surrounding the planet and occulting the star at Lyman-alpha. The timing requirements are set as phase constraints on the first ACQ exposure of the first orbit in a visit, with allowed start phase range of 25 min. Visits could be reduced to 4 HST orbits each if scheduling proves too difficult, however our science goals would be better reached with 5 orbits. Two orbits before the planet transit are required to measure the flux from the unocculted star, one orbit is scheduled during the nominal planet transit (when absorption from a putative extended exosphere is maximum), and two orbits scheduled after the transit will allow us to search for and characterize an exospheric tail trailing the planet. We set BETWEEN constraints for the two visits to avoid time windows when other planets in the system (GJ9827b and GJ9827c) transit as well. Ideally the two visits should further be scheduled between July 25th 2019 and December 13rd 2019, or between July, 25th 2020 and December, 13rd 2020 to reduce airglow contamination. It would be best for our science goals if the two visits could be scheduled as close as possible to each other, and as closes as possible to the start of these windows. These constraints can however be removed if scheduling proves too difficult. We use the same settings as GO#15434, which used STIS/FUV-MAMA and the G140M grism centered on a wavelength of 1,222 to observe the transit of GJ9827b at Lyman-alpha. Investigators V. Bourrier, D. Ehrenreich, and B. Lavie have a long experience in UV observations of exoplanets and their theoretical interpretations (totaling 16 first-author publications about evaporating exoplanets based on HST data). V. Bourrier and D. Ehrenreich led the first UV searches for exospheres around super-Earth and Earth-size planets (as principal investigators of 6 and 4 previous HST proposals on this topic). Investigators L. Dos Santos and B. Lavie will use their expertise to contribute new analysis tools for the proposed observations, as they analyzed HST UV spectra from GO14222 and 14767 in the frameworks of their PhD thesis (Lavie+2017; Dos Santos+2018). Investigator R. Allart is leading a ground-based HARPS program on the GJ9827 system targeting the intermediate atmospheric layers of planets b and d, and has thus valuable experience on the system. Investigator V. Bourrier developed a 3D numerical model of upper atmospheres (the EVE code, e.g. Bourrier+2016) that has been used to interpret the UV observations of most known evaporating gaseous planets in terms of atmospheric mass loss, dynamical, and density structure (e.g., Bourrier & Lecavelier 2013; Ehrenreich+2012, 2015; Bourrier+2014, 2016b, 2017a, 2017c). The EVE code will be applied to both archival observations of GJ9827b and the proposed observations of GJ9827d, and linked with lower atmospheric models co-developed by investigator M. Turbet (expert in the atmosphere and climate of Solar System and extrasolar planets), which have previously been used and tested on similar exoplanetary objects (Charnay+2015a, b). Planets and Planet Formation Stellar Physics 6 false false true false false false false SUPPORTED STAR EXTRA-SOLAR PLANET K V-IV NO All target properties come from the SIMBAD database. We used the confirmation charts to check that the coordinates and proper motion were correct. K2-135 BD-02D5958 J2000 J2000 B =11.57 ,R =10.09 ,I =8.89 ,G =9.8377 ,J =7.984 ,H =7.379 ,K =7.193 , i = 9.18 STIS/FUV-MAMA Spectroscopic No No G140M 1222 STIS/FUV-MAMA Spectroscopic No No G140M 1222 The scheduling data was generated by CASM 27.2. CASM was run in Phase II mode. /private/var/folders/33/rs56p2wx5q174bfyvvm_nq1m0000gn/T/OPVisit4734663770577194727.xml We set a BETWEEN constraint to limit airglow contamination (Tic-Visit :proposal-id 15859 :visit-id "01" :proposal-version -1 :trans-version "20190514" :date "29-Nov-2019 11:31:56.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 1062048 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15859 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15859 :visit-id "01" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2525 :al-overhead-at-end 0 :internal-dur-at-end 360 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2918 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15859 :visit-id "01" :orbit-number 2 :pcs-time 302 :si-vis-utilization 2616 :al-overhead-at-end 0 :internal-dur-at-end 360 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2918 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15859 :visit-id "01" :orbit-number 3 :pcs-time 302 :si-vis-utilization 2616 :al-overhead-at-end 0 :internal-dur-at-end 360 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2918 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15859 :visit-id "01" :orbit-number 4 :pcs-time 302 :si-vis-utilization 2616 :al-overhead-at-end 0 :internal-dur-at-end 360 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2918 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15859 :visit-id "01" :orbit-number 5 :pcs-time 302 :si-vis-utilization 2616 :al-overhead-at-end 0 :internal-dur-at-end 622 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2918 :pcs-gap 0 ) true 5 0 Same settings as GO#15434 Same settings as GO#15434 Same settings as GO#15434 The scheduling data was generated by CASM 27.2. CASM was run in Phase II mode. /private/var/folders/33/rs56p2wx5q174bfyvvm_nq1m0000gn/T/OPVisit10041763630535637993.xml We set a BETWEEN constraint to limit airglow contamination (Tic-Visit :proposal-id 15859 :visit-id "02" :proposal-version -1 :trans-version "20190514" :date "29-Nov-2019 11:32:00.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "24" :si-bright-earth-limb-angle 20.0 :data-volume 1062048 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15859 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15859 :visit-id "02" :orbit-number 1 :pcs-time 393 :si-vis-utilization 2525 :al-overhead-at-end 0 :internal-dur-at-end 360 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2918 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15859 :visit-id "02" :orbit-number 2 :pcs-time 302 :si-vis-utilization 2616 :al-overhead-at-end 0 :internal-dur-at-end 360 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2918 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15859 :visit-id "02" :orbit-number 3 :pcs-time 302 :si-vis-utilization 2616 :al-overhead-at-end 0 :internal-dur-at-end 360 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2918 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15859 :visit-id "02" :orbit-number 4 :pcs-time 302 :si-vis-utilization 2616 :al-overhead-at-end 0 :internal-dur-at-end 360 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2918 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15859 :visit-id "02" :orbit-number 5 :pcs-time 302 :si-vis-utilization 2616 :al-overhead-at-end 0 :internal-dur-at-end 622 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2918 :pcs-gap 0 ) true 5 0 Same settings as GO#15434 Same settings as GO#15434 Same settings as GO#15434